1. Field of the Invention
The present invention relates to bearing housings and more particularly to bearing housings incorporating an out-take for oil scavenging in order to achieve better oil regulation within a bearing.
2. Description of Related Prior Art
Operation of bearings is well known and generally comprises bearing components appropriately lubricated and cooled by an oil. This oil is injected appropriately and presented to the bearing as required. Clearly, it is desirable to achieve an acceptable level of oil flow through the bearing rather than create long residence times for that oil within the bearing. It will be understood that long residence times will inevitably allow heating of the oil and therefore cause degradation of that oil as well as higher temperatures for the bearing itself.
In order to achieve good oil flow through a bearing, it is common practice to provide some form of oil scavenging. Oil scavenging involves creating a bias towards oil flow through the bearing. One way of creating that bias is utilising the centrifugal forces of rotation of a bearing such that oil is scattered from an outer peripheral edge of the bearing. This scattered oil may be collected in a volute such that utilising gravity or the centrifugal draft effect of bearing rotation or a specific vacuum pump biases flow towards a scavenge out-take is achieved.
Clearly, if the centrifugal draft effect of bearing rotation is to be utilised then provision of a relatively wide chordal arc opening in a casing for the bearing may create pressure loss problems. In such circumstances, previously a single radial scavenge out-take has been utilised at or near the bottom dead centre of the housing. In such circumstances the scattered oil collects in a sump action towards that scavenge out-take. In such circumstances the out-take does not take full advantage of the inherent bearing rotation centrifugal forces to facilitate oil scavenging.